The inventive concept relates to a water-soluble adhesive, a method of forming the water-soluble adhesive, a pellicle including the water-soluble adhesive, a photomask assembly including the pellicle, a method of attaching the pellicle to the photomask, and a method of detaching the pellicle from the photomask and cleaning the pellicle.
A pellicle may be attached to a photomask to protect optical pattern regions of the photomask. A pellicle may include optically transparent membranes. Since a pellicle is consumable, after a pellicle has been used in a photolithography process for a predetermined time, the pellicle may be replaced with a new one. In order to replace the pellicle, the used pellicle may be physically detached from the photomask. After the pellicle is detached, pellicle adhesive residue may remain on the photomask. When an acid or hydrogen peroxide is used to remove the pellicle adhesive residue, the photomask may be damaged and haze defects may occur on the photomask.